To get what you need to make a relic, you generally need one 'ingredient' that's appropriate to the item's theme per dot of power BEFORE curses, restrictions, and costs are factored in. In general, I'll trust players to run their own little scenes for this. An ST of course can be asked to do so as well, and for high dot powers it might be a good idea (As an ST-run scene might lower the number of ingredients needed in total based on difficulty).
If particularly rare or dangerous things are added, as appropriate to your template's power level (That is, vampire fangs for a non-ghouled mortal, for instance), an ST might waive some of the item amount as well.
Creation is by the book. Dexterity + Crafts, Manipulation + Expression, or another appropriate extended roll is made. Generally, 5 successes are needed. After that, Resolve + Occult is rolled as an extended action, one hour per roll, with a roll cap equal to the BASE dice pool there (Specs count, equipment doesn't), and 5 successes are needed per dot of the final rating of the relic. Remember fatigue penalties; your character should probably start this early in the day.
Temporary relics made that are activated (As opposed to something passive, like the Sense the Unnatural power) generally work one time, plus an additional time for every 5 extra successes earned on the magic roll past what's needed. Passive or 'Permanent' relic powers (such as equipment bonuses) last for a week, plus another week per 5 extra successes. If a relic has both powers, just combine the above.
Remember that relic powers, curses, and other components need to make sense and be thematic. If making, for instance, a bottle used to capture a spirit, why would it grant you Potent Success for Weaponry rolls?
Unique Powers from the relics in the book are clarified here and can be used for temporary or permanent Relics:
Gear-Tooth Prophecy (***) (p. 44): Can be used without being 'machinery' or paper-fed. It has 2 points worth of cost, which by default is a 2 dot ritual action and an appropriate roll, but this can be replaced as is thematic to your specific item. The prophecy is of course only as accurate as an online chat can ever be.
Ancient Source of Energy (**) (p. 46): Generally, this has a 2 dot 'ritual' cost for the low power, one hour duration use, and a 4 dot ritual cost for the version that lasts for a week and can power a full home. As usual, this can be replaced with different costs as is thematic to your item.
Eye Opener (*****) (p. 49): Permanent items only.
Beacon (** Curse) (p. 50): Generally, this curse would be applied to a certain type of MALEVOLENT entity, rather than the agents specific to the book's relic. Note, I say malevolent, and I mean actively so. Your character having a phobia of fluffy bunny spirits doesn't mean attracting them is appropriate.
Dream (0 dot, effectively a 2 dot Power and 2 dot Curse combined) (p. 50): The only thing to clarify is that the Wits + Resolve roll is affected by anything that'd affect a dream's Intensity (via Changeling).
Surprising Weapon (*) (p. 56): This can only be applied to an item that shouldn't normally be a weapon. The most its rating will be is +2, bashing damage, with the +3 init.
Spotlight on the Gods (***) (p. 57): This doesn't need to be a light, the power is just SOME mechanism that makes twilight beings visible to anyone around.
Revelation (***) (p. 58): Permanent items only. The mechanism should be similar to the one in the book, one month of some uninterrupted activity, usable once on the relic, to gain a permanent +1 bonus to Occult or Science rolls (Or some other Mental skill roll as appropriate to the object). This can get out of hand fast, so I don't want to see many of these types of objects around.
Custom powers can be applied to relics, with ST approval. Approved powers can be added here:
Infusion (**): This power is similar to Battery of Will on pg 88, but rather than being used to store willpower, it's used to store an energy trait of some type (Mana, Glamour, Vitae, etc) at a 2 for 1 ratio that can then be drawn reflexively, but this counts towards energy use per turn. Only one type per item, unless it's bought at 4 dots instead.